Experimental study on engineering mechanical properties of loess-like backfill under various conditions

Abstract

Aiming at the loess-like backfill soil in the Lanzhou area, the samples with different compaction coefficients and different moisture content were prepared in the laboratory and tested by a double-line method. In the analysis of compression deformation, the pore ratio change rate is introduced, and the interval with the pore ratio change rate less than 10% is defined as the corresponding insignificant compression area. The corresponding compaction coefficient and water content of this area are summarized. The critical compaction coefficient is introduced in the analysis of collapsible deformation, according to which the subdivision is carried out, and the corresponding compaction coefficient and water content of the non-collapsible area are summarized. According to the variation curves of the subsidence coefficient under different compaction coefficients, the deformation mechanism of backfill soil after flooding is discussed. It is divided into two areas: water-compression area (low-pressure solid area) and water-subsidence area (high-pressure solid area).